Classifications

• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
  • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
  • G06F3/03—Arrangements for converting the position or the displacement of a member into a coded form
  • G06F3/041—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means
  • G06F3/046—Digitisers, e.g. for touch screens or touch pads, characterised by the transducing means by electromagnetic means
• • G—PHYSICS
  • G06—COMPUTING; CALCULATING OR COUNTING
  • G06F—ELECTRIC DIGITAL DATA PROCESSING
  • G06F3/00—Input arrangements for transferring data to be processed into a form capable of being handled by the computer; Output arrangements for transferring data from processing unit to output unit, e.g. interface arrangements
  • G06F3/01—Input arrangements or combined input and output arrangements for interaction between user and computer
  • G06F3/02—Input arrangements using manually operated switches, e.g. using keyboards or dials
  • G06F3/0202—Constructional details or processes of manufacture of the input device
• • H—ELECTRICITY
  • H03—ELECTRONIC CIRCUITRY
  • H03K—PULSE TECHNIQUE
  • H03K2217/00—Indexing scheme related to electronic switching or gating, i.e. not by contact-making or -breaking covered by H03K17/00
  • H03K2217/94—Indexing scheme related to electronic switching or gating, i.e. not by contact-making or -breaking covered by H03K17/00 characterised by the way in which the control signal is generated
  • H03K2217/96—Touch switches
  • H03K2217/96038—Inductive touch switches

Definitions

• the present disclosure relates to inductive touch sensors, and more particularly, to an inductive touch sensor using a flexible coil.
• Inductive touch sensor technology may be used as an alternative to capacitive touch sensor technology.
• Current technology inductive touch sensors comprise a target (surface being touched or pressed), a spacer and an inductance coil. When the target is actuated (e.g., touched) the coil inductance changes value. Detection of this change in the inductance value of the coil indicates actuation of the inductive touch sensor.
• Manufacturing of an inductive touch panel comprise a plurality of inductive touch sensors, and requires assembly of a sensor etched and sandwiched on a printed circuit board (PCB), generally at final assembly of a product. The spacer must be placed between the PCB which contains the inductance coils, one for each key or button, and the targets for each key or button.
• Current manufacturing technologies consist of producing the PCB, the spacer, laminating the spacer to the PCB and then mounting the PCB/Spacer assembly to the target panel. Tight tolerances are required between the target and the inductive coil that will change its inductance value.
• an inductive touch sensor may comprise: a flexible substrate; an inductor in mechanical communication with the flexible substrate, the inductor and the flexible substrate having a first position and a second position, wherein the flexible substrate and the inductor assume the second position when a force is applied thereto; and wherein the inductor has a first inductance value when in the first position and a second inductance value when in the second position.
• the first inductance value is greater than the second inductance value. According to a further embodiment, the first inductance value is less than the second inductance value.
• the flexible substrate has openings therein to allow distances between coil turns of the inductor to increase and decrease depending upon whether or not the force is being applied to the flexible substrate and inductor. According to a further embodiment, the distances between the coil turns increase when the force is applied. According to a further embodiment, the distances between the coil turns decrease when the force is applied.
• the flexible substrate and inductor are substantially flat when the force is not applied thereto, and concave when the force is applied thereto. According to a further embodiment, the flexible substrate and inductor are convex when the force is not applied thereto, and less convex when the force is applied thereto. According to a further embodiment, the flexible substrate and inductor are convex when the force is not applied thereto, and substantially flat when the force is applied thereto. According to a further embodiment, the inductor is embedded in the flexible substrate. According to a further embodiment, the inductor is coterminous with the flexible substrate.
• a support substrate and ridge spacers between the support substrate and the flexible substrate are added, wherein the support substrate, ridge spacers and flexible substrate form a cavity.
• the cavity is filled with a flexible material.
• a conductive ground plane in the cavity and on an inside face of the support substrate is added, wherein the conductive ground plane influences the second inductance value of the inductor when in the second position.
• a magnetic material is added in the cavity and on an inside face of the support substrate, wherein the magnetic material influences the second inductance value of the inductor when in the second position.
• the magnetic material is selected from the group consisting of ferrite and powered iron.
• an electronic circuit is coupled to the inductor for measuring inductance values thereof.
• the electronic circuit is a mixed signal integrated circuit device.
• an inductive touch sensor panel may comprise: a flexible substrate divided into a plurality of touch key areas arranged in a matrix; a plurality of inductors in mechanical communication with the flexible substrate, each of the plurality of inductors associated with a respective one of the plurality of touch key areas, each of the plurality of inductors and the plurality of touch key areas having a first position and a second position, wherein each touch key area and inductor assume the second position when a force is applied thereto; wherein the inductor has a first inductance value when in the first position and a second inductance value when in the second position; a support substrate; and ridge spacers between the support substrate and each of plurality of touch key areas, wherein the support substrate, ridge spacers and the plurality of touch key areas form a plurality of cavities.
• an inductive touch sensor may comprise: a flexible substrate; a support substrate; ridge spacers between the support substrate and the flexible substrate, wherein the support substrate, ridge spacers and flexible substrate form a cavity; an inductor comprising a coiled spring, a first end of the inductor is in mechanical and electrical communications with the flexible substrate and a second end of the inductor is in mechanical and electrical communications with the support substrate; the inductor has a first inductance value when in a first position and a second inductance value when in a second position; and the inductor assumes the second position when a force is applied to the flexible substrate.
• Figure 1 illustrates schematic plan views of an inductor that is formed as a spiral coil of an inductive touch key for non-actuated and actuated conditions, according to a specific example embodiment of this disclosure
• Figure 2 illustrates schematic plan views of an inductor that is formed as a spiral coil of an inductive touch key for non-actuated and actuated conditions, according to another specific example embodiment of this disclosure
• Figure 3 illustrates schematic elevational cutaway views of the inductor of the inductive touch key shown in Figures 1 or 2, according to specific example embodiments of this disclosure
• Figure 4 illustrates schematic elevational cutaway views of the inductor of the inductive touch key shown in Figures 1 or 2, according to specific example embodiments of this disclosure
• Figure 5 illustrates schematic elevational cutaway views of an inductive touch key using the inductor and substrate shown in Figure 4, according to a specific example embodiment of this disclosure
• Figure 6 illustrates schematic elevational views of an inductor that is formed as a spring coil of an inductive touch key for non-actuated and actuated conditions, according to yet another specific example embodiment of this disclosure
• Figure 7 illustrates schematic elevational cutaway views of an inductive touch key using the inductor shown in Figure 6, according to specific example embodiments of this disclosure
• Figure 8 illustrates a schematic frontal view of an inductive touch keypad showing an inductive sense coil that is typical for all keys of the keypad, according to specific example embodiments of this disclosure.
• Figure 9 illustrates a schematic block diagram of an electronic system having an inductive touch keypad as shown in Figure 6, an inductive touch analog front end and a digital processor, according to specific example embodiments of this disclosure.
• An inductive touch sensor comprises an inductor disposed in or on a deformable substrate. When a force is applied to the deformable substrate the physical shape of the inductor changes and thereby changes its inductance value. The change in the inductance value can be detected and used to indicate actuation of an associated touch key of the inductive touch sensor.
• a plurality of inductive touch sensors may be used to form a touch panel.
• FIG. 1 depicted are schematic plan views of an inductor that is formed as a spiral coil of an inductive touch key for non-actuated and actuated conditions, according to a specific example embodiment of this disclosure.
• An inductor coil 102a is shown in a non-actuated state, and the inductor coil 102b is shown in an actuated state, as more fully described hereinafter.
• the inductor coil 102 is wound in a substantially flat spiral configuration in or on a deformable substrate 104 (see Figures 3 and 4).
• This change in the inductance value can be measured and used to indicate activation of the inductor coil 102 by an external force, e.g., finger push.
• Electrical connections 522 and 524 are adapted to couple the inductor coil 102 to electronic measurement circuits (not shown) for determination of the inductance value thereof. It is contemplated and within the scope of this disclosure that slots may be cut in the deformable substrate 104 so as to facilitate separation of the coil turns.
• FIG 2 depicted are schematic plan views of an inductor that is formed as a spiral coil of an inductive touch key for non-actuated and actuated conditions, according to another specific example embodiment of this disclosure.
• the inductor coil 102a is shown in a non-actuated state, and the inductor coil 102c is shown in an actuated state, as more fully described hereinafter.
• the inductor coil 102 is wound in a substantially flat spiral configuration in or on a deformable substrate 204 (see Figures 3 and 4).
• the electrically conductive turns of the inductor coil 102 will become farther apart (separate) as shown in the (b) drawing of Figure 2.
• the deformable substrate 204 is shown deformed, e.g., stretched, in one dimension. (X axis).
• a third dimension (Z-axis is shown in Figures 3 and 4) also stretches the substrate 204 to further increase the distance between the coil turns. By increasing the separation between the coil turns, the inductance value of the inductor coil 102 will decrease.
• This change in the inductance value can be measured and used to indicate activation of the inductor coil 102 by an external force, e.g., finger push. It is contemplated and within the scope of this disclosure that slots may be cut in the deformable substrate 104 so as to facilitate separation of the coil turns.
• FIG. 3 depicted are schematic elevational cutaway views of the inductor of the inductive touch key shown in Figures 1 or 2, according to specific example embodiments of this disclosure.
• the inductor coil 102 is shown embedded into the flexible substrate 104.
• substrate 104 does not have a force on its face then there is no deformation thereof and the turns of the coil 102a are spaced at a distance d, therebetween.
• the coil 102a configuration will have a first inductance value.
• a force 306 is applied to a face of the substrate 104, deflection thereof occurs and the turns of the coil 102b become farther apart.
• the turns of the coil 102b are spaced at a distance da therebetween, where da > di.
• the coil 102b has a second inductance value that is less than the first inductance value. This is easily measured by electronic circuits.
• the coil 102 may be fabricated on a surface of the substrate 104 (coterminous), or the coil 102 may be fabricated without any substrate at all.
• the coil 102 may be self supporting and deformably springy so as to return to its un-actuated shape. So long as the shape of the coil 102 changes wherein the distance between the turns thereof change, so will the inductance value thereof change.
• the substrate 104 is normally flat when no force 306 is applied to its surface (face), and becomes concave when the force 306 is applied thereto.
• FIG 4 depicted are schematic elevational cutaway views of the inductor of the inductive touch key shown in Figures 1 or 2, according to specific example embodiments of this disclosure.
• the inductor coil 102 is shown embedded into a convex curved flexible substrate 204.
• the convex curved substrate 204 does not have a force on its face then there is no deformation thereof, the face thereof remains convex, and the turns 310 of the coil 102a are spaced at a distance d t therebetween.
• the coil 102a configuration will have a third inductance value.
• a force 306 is applied to a convex face of the substrate 204, deflection thereof occurs and the turns 10 of the coil 1 2b become closer together.
• the turns 3 10 of the coil 102b are spaced at a distance dk therebetween, where d s > d. ( .
• the coil 102b has a fourth inductance value that is greater than the third inductance value. This is easily measured by electronic circuits.
• the coil 102 may be fabricated on a surface of the convex substrate 204, or the coil 102 may be fabricated without any substrate at all.
• the coil 102 may be self supporting and deformably springy so as to return to its un-actuated shape. So long as the shape of the coil 102 changes wherein the distance between the turns thereof change, so will the inductance value thereof.
• the substrate 204 is normally convex curved when no force 306 is applied to its surface ( face), and may become substantially flat (e.g., less convex curved) when the force 306 is applied thereto.
• the configuration shown in Figure 4 is easily adapted to raised, tactile touch keys on a keypad (see Figure 8).
• An inductive touch key generally represented by the numeral 500, comprises inductor coil 102 having turns 310 embedded in a convex curved flexible substrate 504 that is attached to ridged supports 518 and 520. These ridged supports 518 and 520 space the substrate 504 from a support substrate 512, e.g., printed circuit board (PCB), that may be common to a plurality of inductive touch keys 800 (see Figure 8).
• a deformable space 508 is disposed between the convex curved flexible substrate 504 and the support substrate 512.
• the deformable space 508 may be air or gas (empty), or it may be filled with a deformable material, e.g., foam, silicon gel, etc.
• a magnetic material 510 e.g., ferrite, powered iron, etc., having properties that influence the inductance value of the coil 102, may be located in the space 508.
• a conductive ground plane 514 may be disposed on a face of the support substrate 512 and connected to ground or a power source common 526 with, for example, a printed circuit board via 516. The purpose of this conductive ground plane 514 is to influence (increase) the inductance value of the coil 102 as the turns 310 of the coil 102 are moved closer to it, drawing (b) showing force 306 applied to a face of the convex curved flexible substrate 504.
• FIG. 6 depicted are schematic elevational views of an inductor that is formed as a spring coil of an inductive touch key for non-actuated and actuated conditions, according to yet another specific example embodiment of this disclosure.
• An inductor coil 702a is shown in a non-actuated state, and the inductor coil 702b is shown in an actuated state, as more fully described hereinafter.
• the inductor coil 702 is wound in a deformable spring shape.
• a force 306 e.g., finger push
• the inductance value of the inductor coil 702 will increase. This change in the inductance value can be measured and used to indicate activation of the inductor coil 702 by an external force, e.g., finger push.
• An inductive touch key generally represented by the numeral 700, comprises a spring shaped inductor coil 702, a convex curved flexible substrate 704 that is attached to ridged supports 718 and 720. These ridged supports 718 and 720 space the substrate 704 from a support substrate 712, e.g., printed circuit board (PCB), that may be common to a plurality of inductive touch keys 800 (see Figure 8).
• a deformable space 708 is disposed between the convex curved flexible substrate 704 and the support substrate 712.
• the deformable space 708 may be air or gas (empty), or it may be filled with a deformable material, e.g., foam, silicon gel, etc.
• a conductive ground plane 714 may be disposed on a face of the support substrate 712 and connected to ground or a power source common 724 with, for example, a printed circuit board via 7 16.
• the purpose of this conductive ground plane 7 14 is to connect one end of the coil 702 and the other end of the coil 702 is connected with a conductor 722 that may be a flexible conductor disposed on an inside surface of the convex curved flexible substrate 704.
• a force 306 is applied to the face of the convex curved flexible substrate 704, the coil 702 is compressed, thereby increasing its inductance value, compare drawing (a) to drawing (b) of Figure 7.
• Electrical connections 722 and 724 are used to couple the inductor coil 702 to electronic measurement circuits (see Figure 9) for determining the inductance value thereof.
• FIG. 8 depicted is a schematic frontal view of an inductive touch keypad showing an inductive sense coil that is typical for all keys of a keypad, according to specific example embodiments of this disclosure.
• a keypad generally represented by the numeral 800, is configured as a matrix of inductive touch sensor keys 804 comprising a plurality of inductive touch sensors 802.
• a coil 802 having an inductance value that changes when a force 306 is applied thereto, as more fully described hereinabove.
• a digital processor 950 e.g., a microprocessor, microcomputer, digital signal processor (DSP), application specific integrated circuit (ASIC), programmable logic array (PLA), etc.
• DSP digital signal processor
• ASIC application specific integrated circuit
• PPA programmable logic array
• AFE inductive touch analog front end
• the digital processor 950 and AFE 952 may be part of a mixed signal (analog and digital circuits) integrated circuit device.
• the inductive touch AFE 952 facilitates, with a single low-cost integrated circuit device, all active functions used in determining when there is actuation of inductive sensors, e.g., by pressing and deflecting a target key that changes the inductance value of an associated inductive sensor.
• the inductive touch AFE 952 measures the inductance value of each sensor of the matrix of inductive touch sensor keys 800 and converts the inductance values into respective analog direct current (dc) voltages that are read and converted into digital values by the digital processor 950. It is contemplated and within the scope of this disclosure that standard analog components may be used to make a discrete analog front end (AFE), and that one having ordinary skill in electronic circuit design and the benefit of this disclosure could readily design such a discrete AFE.
• AFE analog front end
• the digital processor 950 supplies clock and control functions to the inductive touch AFE 952, reads the analog voltage detector output of the inductive touch AFE 952, and selects each key of the matrix of inductive touch sensor keys 800. When actuation of a key of the matrix of inductive touch sensor keys 800 is determined, the digital processor 950 will take an appropriate action as programmed therein.

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Theoretical Computer Science (AREA)
• Physics & Mathematics (AREA)
• Human Computer Interaction (AREA)
• General Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Switches That Are Operated By Magnetic Or Electric Fields (AREA)
• Push-Button Switches (AREA)
• Coils Or Transformers For Communication (AREA)
• Input From Keyboards Or The Like (AREA)

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• 2012
  • 2012-01-20 US US13/355,206 patent/US9983757B2/en active Active
• 2013
  • 2013-01-17 WO PCT/US2013/021833 patent/WO2013109687A1/en active Application Filing
  • 2013-01-17 KR KR1020147023114A patent/KR20140135708A/ko active IP Right Grant
  • 2013-01-17 CN CN201380009372.4A patent/CN104137032B/zh not_active Expired - Fee Related
  • 2013-01-17 JP JP2014553392A patent/JP6116588B2/ja active Active
  • 2013-01-17 EP EP13702153.1A patent/EP2805216A1/de not_active Withdrawn
  • 2013-01-18 TW TW102102108A patent/TWI599940B/zh active

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